The present invention generally deals with prolonging the shelf life and the period of resistance against microorganisms of cosmetic products.
The cosmetic industry has long been concerned about preventing deterioration and prolonging the shelf life of cosmetics. On prolonged use, a cosmetic is subject to change in its activity, may become unstable or may separate into its ingredients.
Known methods to overcome these difficulties require the incorporation of bacteriostatic agents as preservatives and antioxidants to limit autoxidation or involve costly procedures such as preparation of the cosmetic formulations in a vacuum. The preservatives used in the prior art are often inadequate in preventing microbial and fungal action on naturally occurring substances incorporated in a cosmetic product. These products are therefore overloaded with preservatives. Cosmetics infested with fungi or other microorganisms when applied continuously to the skin may cause local infections especially where slight abrasions or cuts are present.
Many preservatives become chelated or sequestrated from the lipophilic phase of the emulsifier so affecting the stability and sterility of the cosmetics.
The antioxidants used in cosmetics have a limited active life. They can be used only in small quantities since they irritate the skin as has been described in scientific publication on allergies and other skin problems.
Particularly the activity of naturally occurring active ingredients in the cosmetic products such as vitamins and hormones is significantly reduced through these conventional cosmetic preparations.